Design of ligand attachment chemistry for high conductivity polymer electrolytes

Abstract

A composition of matter useful in an electrolyte, comprising a polymer including: a repeat unit, the repeat unit including a backbone section; and a side chain attached to the backbone section, wherein the side chain includes a ligand moiety configured to ionically bond to a lithium ion. The polymer has a glass transition temperature (e.g., less than room temperature) wherein the polymer is in a solid state during operation of a lithium ion battery comprising an electrolyte including the polymer.

What is claimed is: 
     
         1 . A polymer, comprising:
 a plurality of repeat units, each of the repeat units including a backbone section; and   a plurality of side chains, each of the side-chains attached to a different one of the backbone sections, wherein:   at least, some of the side chains include a spacer connected to a ligand moiety, the ligand moiety configured to bond to, or interact with, a cation so as to at least solvate or conduct the cation,   the spacer does not conduct or solvate the cation, and   the spacer is 4 atoms-20 atoms long.   
     
     
         2 . The polymer of  claim 1 , wherein the glass transition temperature is less than 40 degrees Celsius or less than 50 degrees Celsius. 
     
     
         3 . The polymer of  claim 1 , wherein the spacer at least:
 does not include nitrogen or oxygen, or   consists essentially of at least one of carbon, silicon, sulfur, phosphorus, hydrogen.   
     
     
         4 . The polymer of  claim 1 , wherein the spacer comprises at least one of an alkane, an ether, a siloxane, a thiol ether. 
     
     
         5 . The polymer of  claim 1 , wherein the ligand moiety comprises an electron rich group or a group comprising an electron lone pair. 
     
     
         6 . The polymer of  claim 1 , wherein the spacer does not include an amide. 
     
     
         7 . The polymer of  claim 1 , wherein the ligand moiety comprises an imidazole or cyano. 
     
     
         8 . The polymer of  claim 1 , wherein the polymer has one of the following structures: 
       
         
           
           
               
               
           
         
         wherein BR, BR1, BR2 comprise the backbone section, L1 and SC comprise the spacer, LU, LU1, LU2 comprise the ligand moiety, and x, y, and N are integers and wherein the ligand moiety comprises at least one group selected from: 
       
       
         
           
           
               
               
           
         
       
     
     
         9 . The polymer of  claim 8 , wherein the backbone section comprises one of the following: 
       
         
           
           
               
               
           
         
         and n and m are integers in a range of 5-5000. 
       
     
     
         10 . The polymer of  claim 1 , wherein:
 the polymer has a ligand moiety content such that the Li +  to ligand moiety molar ratio in an electrolyte comprising the polymer is in a range of 0.07 and 0.6, and/or   the polymer has a ligand moiety such that the glass transition temperature is below 40 degrees Celsius and the polymer has the conductivity for the cation, comprising a lithium ion, of at least 10 −5  cm −1  at the temperature of 30 degrees Celsius.   
     
     
         11 . The polymer of  claim 1 , wherein the grafting density of the sidechains is in a range of 50% to 90% and is tailored for a conductivity of a Lithium ion in an electrolyte comprising the polymer. 
     
     
         12 . The polymer of  claim 1 , wherein not ail the sidechains comprise the ligand moiety. 
     
     
         13 . The polymer of  claim 1 , wherein the polymer comprises a bottlebrush polymer. 
     
     
         14 . An electrolyte comprising the polymer of  claim 1 , wherein the cation is Li + . 
     
     
         15 . The electrolyte of  claim 14 , further comprising an additive for increasing the conductivity of the cation in the electrolyte. 
     
     
         16 . A battery comprising the electrolyte of  claim 14  in contact with an anode and a cathode, wherein the polymer has the ligand moiety configured for solvating and conducting the lithium ions in the electrolyte and having a glass transition temperature such that the polymer is in a solid state during operation of the lithium ion batten with the electrolyte comprising the polymer. 
     
     
         17 . A polymer comprising the structure: 
       
         
           
           
               
               
           
         
         where m and n are integers, M is a monomer unit, and S is Sulfur or Carbon. 
       
     
     
         18 . The polymer of  claim 17 , wherein m is in the range 5-15 or 4-20. 
     
     
         19 . A method of making an electrolyte in a lithium ion battery comprising:
 providing a polymer having a ligand moiety configured for solvating and conducting lithium ions in the electrolyte and having a glass transition temperature such that the polymer is in a solid state during operation of the lithium ion battery with the electrolyte comprising the polymer; and   controlling a grafting density or content of the ligand moiety so that the conductivity is at least 10 −5  S cm −1  at 30 degrees Celsius and the glass transition temperature is below 40 degrees Celsius.   
     
     
         20 . The method of  claim 19 , wherein providing the polymer comprises:
 (a) combining at least one of an imidazole, pyrazole, triazole, pyridine, oxazole, thiazole, furan, nitrile, or pyrimidine, with an alkane to form a derivative;   (b) combining sulfur with the derivative to form a thiol; and   (c) combining the thiol with a polymer comprising a siloxane to form the polymer comprising a side chain including the thiol, wherein the combining (c) comprises a thiolene click reaction.